Rescuers confirmed early Sunday that 11 of the 16 trapped miners were alive three days after they became trapped under a flooded colliery pit in central China's Hunan province.

Medical personnel had gone into the pit carrying stretchers and first-aid material, said the rescuers, adding that the 11 miners would be saved out of the pit in three groups and rushed to hospital for further treatment.

Six professional teams of 90 members and more than 1,000 people were at the scene to carry out rescue operations.

Mine floods usually occur when miners drill through to an abandoned shaft that has been allowed to fill with water. Along with gas explosions and cave-ins, they make China's coal mines the world's deadliest, although the death rate has fallen.

Safety improvements have cut annual fatalities by about one-third from a high of 6,995 in 2002. That improvement has come despite a tripling in the output of coal that generates most of China's electrical power.

Technological advances, better training and the closing of the most dangerous, small-scale mining operations have also made rescues more successful, even after several days.

In April 2010, 115 miners were pulled from a flooded mine in the northern province of Shanxi after more than a week underground. The miners survived by eating sawdust, tree bark, paper and even coal. Some strapped themselves to the walls of the shafts with their belts to avoid drowning while they slept.